Subject: Re: boot problems on VIA EPIA boards - patch
To: Gavan Fantom <gavan@coolfactor.org>
From: Dan LaBell <dan4l-nospam@verizon.net>
List: port-i386
Date: 05/12/2005 06:26:50
On May 4, 2005, at 7:28 AM, Gavan Fantom wrote:
> For those folks with non-booting EPIA boards, could you please try
> this patch?
>
> http://frog.coolfactor.org/~gavan/epia_hack.diff
>
> It works on my ML5000, and I'd like to get some data on whether it
> works for other people, too.
>
Is an EPIA with a C3 or an EDEN ? The Eden problem described in list
before
was exactly the same the problem I had with my C3 / Ezra.. Video going
out of range
etc,
So, I tried the patch, tested via building and using dosboot, no luck
though.
> Also, here's a challenge. If you can come up with a satisfactory
> explanation of *why* this patch works, and some experiments to
> demonstrate the correctness of the explanation, you get a cookie.
>
> My assessment is that this is a CPU bug, and that this patch is
> flushing internal buffers that the ljmp should have done. Again, why
> the 1.6 bootloader didn't hit this bug, I don't know.
>
> Any theories or opinions welcome!
Well, I noticed that from 1.6->2.x eax is preserved, but in some places
in 2.x the
caller still saves it.
gcc 2.95.3 , as 2.11.2 in 1.6 vs gcc 3.3.3 as 2.14 in 2.x
producing different code, patch causes gcc to produce code that avoids
bug
>
> (please CC me on replies, as I'm not currently subscribed to port-i386)
>
> --
> Gilette - the best a man can forget
>